The present invention relates to a sailboat and more particularly, to the rig utilizing a free standing mainsail boom.
There are many small boats represented in the prior art that include masts that are stepped by passing through an aperture in the deck and thence into some support means that is connected to the hull of the boat as for example, a mast step or a mast receiving sleeve. Sailfish and Lasers are at least two examples of this type of sailboat having this form of construction for supporting essentially a free standing mast, that is one that does not utilize shrouds. Booms, however, are all attached to the mast in a non-rigid pivoting manner. When the sail, which is generally attached to the mast at the luff edge thereof and also to the boom at the tack and at the clew, there are loads that are developed on the mast by this type of arrangement that are significant. In small boats, it is desirable to reduce the size of the mast to improve the performance and stability of the boat, but this has been difficult in the past due to the significant loads that have been developed. It is also desirable to provide a self supporting boom that in the past has generally been achieved by the use of a hydraulic vang. Jib booms are notoriously poor performers off the wind as they are not able to be vanged. Thus a jib boom swivel mounted at its forward end merely is able to be effective over a small arc while the boom lies essentially over the hull, since it can not be downwardly loaded except in that small arc.
One approach is seen in German Published Application 37 03744, where a self supporting boom is described along with tensioning of the sail leech on the wind and a loosening of the leech tension when the boom is let off, i.e. reaching or running.
It is the prime object of the instant invention to improve on the prior art with a structure by maintaining constant leech tension on the sail throughout boom movement. The object is achieved with a boom having an arcuate forward end terminating in a stub shaft that is received in a socket immediately adjacent and aft of the luff of the sail as structurally permissible, the stub shaft extending on an axis parallel to the luff of the sail.
It is a further object of the invention to provide a self supporting jib boom.
It is a still further object of the invention to eliminate topping lifts and some of the other problems associated with many of the conventionally rigged sailboats including clearance problems due to the swinging of the boom across the cockpit. A more specific object is to eliminate the load between the mast and the boom created by the forces developed by the sail.